Metal article and method of preparing same



May 28, 1935 w. R. SHIMER ET AL METAL ARTICLE AND METHOD OF PREPAfiINGSAME 3 Sheets-Sheet 1 Original Filed Aug. 4, 1930 ay 5- w. R. SHIMER ETAL. 2,003,094

METAL ARTICLE AND ME'fHOD OF PREPARING SAME Original Filed Aug. 4, 1930s Sheets-Sheet 2 y 1935 w. R. SHIMER ETAL 2,003,094

METAL ARTICLE AND METHOD OF PREPARING SAME Original Filed Aug. 4, 1930 3Sheets-Sheet 3 Patented -May 28, 1935 EQUE'IE'AL TECILE IVIETH OD 6FPRE- v v PABDTG SAME William Robert Shimer, Bethlehem, and James A.

ey and Frank 0.

Kichline, Lebanon, Pal,

assignors to Bethlehem Steel Company, a corporation oil PennsylvApplication August 4, 1930, Serial No. 473,004

Renewed October 27, 1934 5 Hart Our invention relates to sucker rods andsimilar articles and methods of preparing same. It also relates tocorrosion resisting articles and methods for. preparing them. Animportant purpose is to obtain sucker rods or similar articles whichshall have mechanical properties superior, to those of the ordinarysucker rod because of subjection to a particularheat treatment. Anotherobject is a sucker rod or other article which shall be relativelyincorrodible' in' service.

Our invention comprises a sucker rod having a normalized structurethrough the greater portion of its length and having a microstructure inthe pin ends resultingv from a rapid cooling through the critical range,such metal structure of the pin end merging gradually into the nor.-malized structure of the remainder of the rod. Furthermore, ourinvention comprises articles, whether sucker rods or other articles,having a surface highly resistant to corrosion producing conditions;

a In presenting our invention we'shall set forth a specific example ofits application but of .course it is to be understood that this exampleis merely illustrative and is not intended to be limiting to theprotection which is sought.

In setting forth the invention we shall first briefly state the steps ofan illustrative process and the cheats produced in a sucker rod and thenlater we shall set forth somewhat more fully the operation whenemploying particular equipment.

First, setting forth an outline of the process: A round bar of diameter,for example, is rolled in the regular way from steel of the fol lowinganalysis: Carbon .25 to .80, manganese .50 to .80, nickel .40 to 1.00,and chromium .20 to 55. This is prepared in the desired lengths, say, 25or 30 feet, for instance, the ends heated in the furnace to atemperature between 2000 and 2250 F. and then subjected to a series ofupsetting or forging operations to form a pin end and wrench square.Next the bar is placed in a furnace and is uniformly heated throughout.itslength to a temperature above the critical range, say from 1550 to1650" F. This may well take about fortyfive minutes. The bar is thenremoved from the furnace and gripped at its two ends, at the wrenchsquares, in gripping mechanism, which will later be described. The baris then placed under ten- 50- sion by exercising a pull on one endagainst a resistance applied to the other end. The pulling 1 force issuddenly applied so that the condition of tension is initiated with asnap,'thereby effecting a straightening of the rod. At about the 55 sametime of placing the rod under tension a cooling fluid is applied to theregion at each end which includes the wrench square and the pin end.This application of cooling fluid is continued until these'resions ofthe sucker rod have been rapidly cooled through the critical range. The5 I streams of ,fluid are discontinued, however, before the greater partof the metal in the remaining regions of the rod has cooled through thecritical, range. The residual heat in the remaining portion of the rodis utilized to eilect a draw" of the 10 quenched regions. Tension ismaintained, in the manner indicated, on the rod until the entire rodpasses through the critical range. I The rods are now released from thegripping mechanism and allowed to cool upon a cooling table until thetemperature has dropped to a temperature of from 600 to 700 F.- While atthis temperature the rod is immersed in a bath of coke oven tar and thenture is uniform throughout the greater portion 5 Q of the rod lengthmerging gradually toward the ends into the structure produced by thequenching-operation. There is no sharp line or zone of demarcationbetween the quenched portions and those portions which were normalizedin the 30 air. The pin ends, and those portions adjoin- .ing the pinends, where failure frequentlyoccurs,

are uniform in structure and much more resistant to failure than withordinary rods.

The manner in which the rod is straightened and the maintaining oftension on the rod during the cooling through the critical range avoidsthe use of any of the ordinary straightening operations which mightintroduce defects or weaknesses in rod structure. 7

The-treatment with tar in some way changes the condition of the surfaceof the metal so as to resist corrosion. Apparently, it is not merely dueto the protection afforded by the coating of tar baked on the surface,as evenbeneath the coating the rod surface is resistant to corrosiveinfluences. Y

Having briefly outlined the process and the eflects of such process, weshall now proceed to a more detailed statement of the invention withreference to the apparatus. empl yed, Accordlngly, referring to thedrawings:

Fig. L is a plan view of the equipment used; Fig. 2 is an endviewlooking in the direction of the arrows 2-2 of 8. 1; 5

Fig.3 is a'detail longitudinal view of the gripping and quenchingmechanism;

in position upon the wrench square l2 at each end of the rod, thepressure of spring 4| serving Fig. 4 is a cross section of the samemechanism to efiect a gripping engagement of fingers 33 taken on theline 4-4 of Fig. 3 and upon the rod. Air is admitted to cylinder 26 Fig.5 is a detail view of the quenching apand cross head 25 is carriedsuddenly to theright, paratus; as viewed in Figs. 1 and 3, jerking therod in the To facilitate an easy understanding of the insame directionand elevating the weight 3|. This vention, it may be well to firstdescribe the jerking action is very important as it serves verystraightening and tensioning and quenching eifectively to eliminate anykinks or other condimechanism, 7 tions tending to prevent straightnessin the rod. Device 22 is adapted to grip one end of sucker At the sametime the rod is placed under a subrod l0 and device 23 the'other end.Device 22 stantial tension. For a rod of cross section such fingers 33.These arms'are provided at an in:

' shank proper of the rod and collar between is connected by means ofchain 24 head 25 mounted on piston 26' of air cylinder 26. compositionand with the particular tempera- Device 23 is connected by means ofchain 21 and tures involved, about 1000 lbs. has been found suitswivel21' to cross head 28 to which is attached able for weight 3|. cable 29passing over pulley 30 and connected The placing of the apparatus androd under to weight'3l. tension as "just outlined, serves to actuate theDevices 22 and 23 are essentially the same in toggles containing links33 to produce an eflecstructure;-therefore a description of one of themtive' gripping of fingers 33 upon the ends of the will'sufilce for both.Arms 32 have rod gripping rod. The motion of cross head 25 serves tooperate erm d at region with lugs 34 which contain contactor 5| whichcloses the circuit through openings 35 whereby the arms may be pivotallysolenoid 5| and thereby serves to open air valve mounted in opposingrelationship on pin 36, 52 to admit air to manifold 46 and thus toprowhich latter is mounted in the inwardly projectduce a flow of airthrough openings 49 of nozzle ing lugs. 31 of supporting body 38.Pivoted to pipes 48 to effect a'rapid cooling of the end regions theouter ends of arms 32 are links 39, which of the sucker rods includingpin end l2, wrench latterare pivotally oonnee ed'to olevis T square l3and collar l4. The air flow continues clevis 40 of device 22 is attachedone end of chain until timer mechanism 53 in the same circuit 24 and toa correspondingclevis of device 23 is opens the circuit through solenoidthereby causve l d an end f chain 21. By means of ing valve 52 to close.The time of the quenching with cross as in the present example and ofthe particular a 13113581011 Spring Placed between a 3 and operationwill vary somewhat but should be sufilheld in position by rod r s 32normally tend cient to permit practically the entire mass of the toeffect 8 ppi g action onfthe rod by pp end regions which are receivingthe flow of air fingers 33. to cool below the critical range. Followingthe S pp r ng bodies 38, which supp rt devices uenching operation theprincipal mass of the 22 nd are provided wi h ir ar an 1' rod is stillabove the critical range and the tires Which r t pon Smooth Plates ,AW hresidual heat in the rod serves to effect a draw 45 of bodies. areprovided with circular holes of th h d tal f the ends.

ou h which pass no e 43 0f the end q Tension is maintained on the roduntil the 8 mechanismentire mass thereof has passed through the Eaoh othe quenching devices Comprises 8 critical-range. When the rod hascooled below manifold 46 which is connected with a source th itic lrange the gripping mechanisms are .of compressed air by means of pipe41. released from the ends of the rod which is allowed nected withmanifold 46 are nozzle Pipes 43 Which to cool to a somewhat lowertemperature on are adapted to pass through the holes in web 45. table2|; Pipes 43 are Provided i opehihgsi disposed The rod is not completelycooled on table 2| i p x ty to the end regions 1 e Sucker d but whilestill at an elevated temperature, say at 3. whereby air may be streamedupon wrench square temperature or from 600 to 700 F., the rod is .l3 andpin ends 12 of the sucker rod. moved therefrom into dipping rack 54wherein Now pro e i to a'descrirtion of the the rod is dipped into abath of tar as and then pl pr The sucker rod h v pin end raisedtherefrom'while still at an elevated tem- Wrench Square d with thethickened perature to permit, the tar to bum on". The portion l3 betweenthe wrench square and therodjs t discharged t stand 55,

, Following the treatment just outlined the pin the Wr nch q re 811d theP end ll, is ro ends are machine turned and threaded. from the stockstand 15 into sins trough Sucker rods thus treated have certain char-This trough is mount d up 2 5 adapted acteristics which especially fitthem for. the parto r p n kw ys The trough mved ticular type ofenvironment in which sucker rods into P i pp grooves of heating IIII-are used. The quenched end and normalized rod nace l8 and th r p shefrom the in structures, merging gradually into each other, t ugh intothe furnace. 1 Here the rod i h t give to the rods just the qualitieswhich enable a Period 01 about y-fi minutes to v them most effectivelyto resist failures in service.

i a temp a 0! from say 5 0 to 6 The treatment with tar produces asurface which t tially un rm fr m end to end of the is very resistant tocorrosion under conditions D a g trough mounted upon t s where the lifeof the ordinary rods is frequently 20' and rolling upon traokwfly ismoved into seriously curtailed on account of corrosive inpositionopposite the rod in furnace 13 and the flugncs,

rod drawn into the trough- Th trough is then Having thus described ourinvention what we moved to table 2l.-: claim and desire to secure byLetters Patent is: Devices 22 and 23 are now brought intoposition 1, Inprocess 01 the class described, the steps at the ends ofthe r d, an ar32 are p s of upsetting the end of a rod, heating the entire litogetherageinst the c n f pr 4| to p rod above the critical range, subjectingsuch rod th nn el en an h e are placed to sufllcient tension tostraighten, qucncm tne end, drawing such the residual heat rod to coolin the quenched end by means of in the rod and allowing the air.

malized structure.

3. In a process for treating articles or the class described, the steps01' upsetting the ends of the rod, heating the entire rod above thecritical range, applying sudden tension to straighten the rod,maintaining said rod under tension, quenching the ends 01' said rod,drawing such quenched ends by means of the residual heat in the rod, andallowing the rod to cool in air through the 3 critical range to producea normalized structure in the rod while maintaining tension thereon.

4. A sucker'rod of steel con carbon between .25% and .80%, nickelbetween .40% and 1.00% andchromium between 20% and .60%. having anormalizedstructure throughout the greater portion of its length, andving a structure in its pin ends resulting from quenching and drawing,the normalized and quenched and drawn metal structures m rging rad allyinto each 4 other.

5. A sucker rod 7 tween 25% and .80%, nickel between 40% and 1.00% andchromium between 20% and .60%, having a normalized structure throughoutat least the greater portion oi its length.

WILLIAM ROBERT SHIMER. JAMES A. KINNEY. FRANK O..KICHLINE.

of swimming when bei Patent No. 2,003,094.

7 CERTIFICATE OF CORRECTION.

May' 28, 1935 WILLIAM AROBERT SHIMER. ET. AL. 0

I t' is hereby certified that error apoeare in the above numbered patentrequiring correction as follow Bryan' M. Better (Sezil) ActingCommissioner of Patents.

